1. Field of the Invention
The present invention pertains to the art of refrigerators and, more particularly, to ice makers for producing clear ice pieces.
2. Description of the Related Art
In general, ice pieces produced with standard ice makers tend to include air bubbles or other imperfections that lend a cloudy or impure appearance to the ice. Therefore, there has been an interest in constructing ice makers which produce clear ice pieces. One approach to preventing the formation of cloudy ice is to agitate or move water in an ice tray during the freezing process. For example, U.S. Pat. No. 4,199,956 teaches an ice making method wherein a plurality of freezing elements are immersed in a pan of water which is agitated by a plurality of paddles during a freezing process. This type of ice maker requires water to be added to the pan every new freezing cycle, and may lead to minerals or other impurities concentrating or collecting in the pan over time. Another approach utilizes the continuous flow of water over a vertical ice-forming plate in a refrigerator compartment to produce ice having a higher purity then that of the original tap water. Specifically, multiple spaced points located on the vertical ice-forming plate are in contact with an evaporator line such that water flowing over the spaced points freezes in layers over time, gradually forming a plurality of ice pieces. In order to harvest the ice pieces, hot refrigerant gas flows into the evaporator line, the warming effect detaches the ice pieces from the ice-forming plate, and the ice pieces fall into an ice bin within the refrigerator compartment. However, large spaces must be left between the contact points of the evaporator in order to prevent ice bridges from developing between ice pieces, thus requiring either relatively large quantities of water to flow over the multiple spaced points, or fewer spaced points. Additionally, this system utilizes the refrigerator's own evaporator, thus requiring specific structure in both the refrigerator and ice maker system. Further, ice pieces collected in the ice bin melt over time, which results in diminished ice quality.
Therefore, there is seen to be a need in the art for improved ice makers for domestic refrigerators that can be utilized with various refrigerator configurations and produce high quality clear ice pieces utilizing minimal amounts of water.